As shown by the U.S. Pat. No. Giler 3,912,905, the use of a molybdenum disilicide resistance wire heating element for a cooking stove hot plate of the glass-top type, is advantageous because when initially powered the resistance wire substantially instantaneously becomes incandescent.
By appropriate proportioning of the resistance wire diameter-to-length factors, the wire can be made to operate at temperatures upwardly from 2000.degree. F. to a service maximum in the area of 2600.degree. F. or possibly higher. Consequently, it is possible to provide an excellent source of thermal radiation for heating a cooking utensil on the glass plate spaced above the heating element.
The Giler patent suggests that the molybdenum disilicide wire element be formed either sinuously or in the form of a spiral with the wire held by being fused to refractory fibers fluffed up from the surface of the usual pad spaced below the glass under the element and made of refractory fibrous material, such as is sold under the tradename "FIBERCHROME" by Johns-Manville. Compacted fibrous refractory pad material is available from other manufacturers under various tradenames.
To more firmly anchor the molybdenum disilicide wire on the refractory fibrous pad, the use of hooks or staples is suggested, made of molybdenum disilicide wire.
The reason for the above is that the prior art has found that molybdenum disilicide wire supports made of metal alloys, normally adapted for elevated temperature service, result in a reaction between the alloy and the molybdenum disilicide when the latter is operating at temperatures of from 2000.degree. to 2600.degree. F., for example.
The use of molybdenum disilicide wire for making staples, loops and the like for supporting the molybdenum disilicide resistance wire has the disadvantage that this compound can be bent only when heated to the high temperature making the material malleable and ductile enough to be bent to the required shapes. This involves a substantial manufacturing cost, and if used in connection with the manufacture of a glass-top electric resistance heater to be incorporated into an electric stove construction, the hot plate overall cost becomes too high relative to other kinds of electric hot plates.